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Browse High School Triangles and Other Polygons
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Selected answers to common questions:
Area of an irregular shape.
Pythagorean theorem proofs.
- What is an N-gon? [06/01/1998]
Can you explain the statement: "In an N-gon, n-3 diagonals can be drawn
from one vertex"?
- What is Length in a Rectangle? [05/31/1999]
Is the length of a rectangle the longest side, whether vertical or
- What is Menelaus' Theorem? [11/15/1998]
Proof of Menelaus' Theorem, and discussion of its converse and Desargues'
- What is the Area Not Shared by the Circles? [3/3/1995]
Two circles intersect such that their centers and their points of
intersection form a square with each side equal to 3. What is the total
area of the sections of the square that are not shared by both circles?
- What Is the Length of PR? [01/01/2003]
In a circle of radius 6, a triangle PQR is drawn having QR=8 and
- Why are Manhole Covers Round? [05/09/2000]
Why are most manhole covers round? Why aren't manhole covers on the
streets squares or rectangles?
- Why a Square Maximizes Area/Perimeter [07/24/2002]
Is it possible to make a rectangle with a perimeter of 16 feet and an
area greater than 16 square feet?
- Why Do the Angles of a Triangle Add to 180 Degrees? [4/17/1996]
We were wondering why all the angles in a triangle add up to 180 degrees.
- Why do the Midpoints of Quadrilaterals Make a Parallelogram? [2/7/1996]
Why is it that if you join the midpoints of any quadrilateral you always
get a parallelogram?
- Why There Is No SSA Congruence Postulate or Theorem [03/29/2005]
In the correspondence of two triangles, if SSA = SSA, are the
- Will the Tree Hit the House? [05/18/1999]
A tree is leaning at 70 degrees, our house is 66 1/2 feet away, and the
angle from our house to the top of the tree is 40 degrees...
- World War II Window Blackout [10/21/2001]
Mr. Brown had a square window 120cm x 120cm, but the only material he
could find was a sheet of plywood 160cm x 90cm; same area, different
shape. He drew some lines and cut out just two congruent shapes, which he
joined to make a square of the correct size. How did he do it?
- You Can't Trisect an Angle [7/16/1996]
Who proved you can't trisect an angle?
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